it.unimi.dsi.Util.identity()方法的使用及代码示例

x33g5p2x  于2022-02-01 转载在 其他  
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本文整理了Java中it.unimi.dsi.Util.identity()方法的一些代码示例,展示了Util.identity()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台,是从一些精选项目中提取出来的代码,具有较强的参考意义,能在一定程度帮忙到你。Util.identity()方法的具体详情如下:
包路径:it.unimi.dsi.Util
类名称:Util
方法名:identity

Util.identity介绍

[英]Stores the identity permutation in a new array of given length.
[中]将身份置换存储在给定长度的新数组中。

代码示例

代码示例来源:origin: it.unimi.dsi/dsiutils

/** Stores the identity permutation in a new array of given length.
 *
 * @param n the size of the array.
 * @return a new array of length <code>n</code>, filled with the identity permutation.
 */
public static int[] identity(int n) {
  return identity(new int[n]);
}

代码示例来源:origin: it.unimi.dsi/dsiutils

/** Stores the identity permutation in a new big array of given length.
   *
   * @param n the size of the array.
   * @return a new array of length <code>n</code>, filled with the identity permutation.
   */

  public static long[][] identity(long n) {
    return identity(LongBigArrays.newBigArray(n));
  }
}

代码示例来源:origin: it.unimi.dsi/webgraph

/** Returns a random permutation for a given graph.
 *
 * @param g an immutable graph.
 * @param seed for {@link XoRoShiRo128PlusRandom}.
 * @return a random permutation for the given graph
 */
public static int[] randomPermutation(final ImmutableGraph g, final long seed) {
  return IntArrays.shuffle(Util.identity(g.numNodes()), new XoRoShiRo128PlusRandom(seed));
}

代码示例来源:origin: it.unimi.dsi/sux4j

/** Solves the system using lazy Gaussian elimination.
 *
 * <p><strong>Warning</strong>: this method is very inefficient, as it
 * scans linearly the equations, builds from scratch the {@code var2Eq}
 * parameter of {@link #lazyGaussianElimination(Modulo3System, int[][], int[], int[], long[])}
 * and finally calls it. It should be used mainly to write unit tests.
 *
 * @param solution an array where the solution will be written.
 * @return true if the system is solvable.
 */
public boolean lazyGaussianElimination(final long[] solution) {
  final int[][] var2Eq = new int[numVars][];
  final int[] d = new int[numVars];
  for(final Modulo3Equation equation: equations)
    for(int v = (int) equation.list.size64(); v-- != 0;)
      if (equation.list.getLong(v) != 0) d[v]++;
  for(int v = numVars; v-- != 0;) var2Eq[v] = new int[d[v]];
  Arrays.fill(d, 0);
  final long[] c = new long[equations.size()];
  for(int e = 0; e < equations.size(); e++) {
    c[e] = equations.get(e).c;
    final LongBigList list = equations.get(e).list;
    for(int v = (int) list.size64(); v-- != 0;)
      if (list.getLong(v) != 0) var2Eq[v][d[v]++] = e;
  }
  return lazyGaussianElimination(this, var2Eq, c, Util.identity(numVars), solution);
}

代码示例来源:origin: it.unimi.dsi/sux4j

/** Solves the system using lazy Gaussian elimination.
 *
 * <p><strong>Warning</strong>: this method is very inefficient, as it
 * scans linearly the equations, builds from scratch the {@code var2Eq}
 * parameter of {@link #lazyGaussianElimination(Modulo2System, int[][], long[], int[], long[])},
 * and finally calls it. It should be used mainly to write unit tests.
 *
 * @param solution an array where the solution will be written.
 * @return true if the system is solvable.
 */
public boolean lazyGaussianElimination(final long[] solution) {
  final int[][] var2Eq = new int[numVars][];
  final int[] d = new int[numVars];
  for(final Modulo2Equation equation: equations)
    for(int v = (int)equation.bitVector.length(); v-- != 0;)
      if (equation.bitVector.getBoolean(v)) d[v]++;
  for(int v = numVars; v-- != 0;) var2Eq[v] = new int[d[v]];
  Arrays.fill(d, 0);
  final long[] c = new long[equations.size()];
  for(int e = 0; e < equations.size(); e++) {
    c[e] = equations.get(e).c;
    final LongArrayBitVector bitVector = equations.get(e).bitVector;
    for(int v = (int)bitVector.length(); v-- != 0;)
      if (bitVector.getBoolean(v)) var2Eq[v][d[v]++] = e;
  }
  return lazyGaussianElimination(this, var2Eq, c, Util.identity(numVars), solution);
}

代码示例来源:origin: it.unimi.dsi/webgraph

/** Renumbers by decreasing size the components of this set.
 *
 * <p>After a call to this method, both the internal status of this class and the argument
 * array are permuted so that the sizes of strongly connected components are decreasing
 * in the component index.
 *
 *  @param size the components sizes, as returned by {@link #computeSizes()}.
 */
public void sortBySize(final int[] size) {
  final int[] perm = Util.identity(size.length);
  IntArrays.parallelRadixSortIndirect(perm, size, false);
  IntArrays.reverse(perm);
  final int[] copy = size.clone();
  for (int i = size.length; i-- != 0;) size[i] = copy[perm[i]];
  Util.invertPermutationInPlace(perm);
  for(int i = component.length; i-- != 0;) component[i] = perm[component[i]];
}

代码示例来源:origin: it.unimi.dsi/webgraph

/**
 * Renumbers by decreasing size the components of this set.
 *
 * <p>After a call to this method, both the internal status of this class and the argument array
 * are permuted so that the sizes of connected components are decreasing in the component index.
 *
 * @param size the components sizes, as returned by {@link #computeSizes()}.
 */
public void sortBySize(final int[] size) {
  final int[] perm = Util.identity(size.length);
  IntArrays.parallelRadixSortIndirect(perm, size, false);
  IntArrays.reverse(perm);
  final int[] copy = size.clone();
  for (int i = size.length; i-- != 0;)
    size[i] = copy[perm[i]];
  Util.invertPermutationInPlace(perm);
  for (int i = component.length; i-- != 0;)
    component[i] = perm[component[i]];
}

代码示例来源:origin: it.unimi.dsi/sux4j

if (! Modulo2System.lazyGaussianElimination(vertex2Edge, c, Util.identity(numVertices), solution)) {
  unsolvable++;
  if (LOGGER.isDebugEnabled()) LOGGER.debug("System is unsolvable");

代码示例来源:origin: it.unimi.di/mg4j

/** Creates an object ready for solving queries.
 * 
 * @param parser the parser to be used when solving queries.
 * @param indexMap the map from index alias to indices.
 * @param graph the graph whence we are going to extract subgraphs.
 * @param grapht the transpose graph, only needed if <code>maxIn</code> or <code>maxOut</code> are positive and finite.
 * @param maxIn how many nodes should be taken (at most) from the in-neighborhood.
 * @param maxOut how many nodes should be taken (at most) from the out-neighborhood.
 * @param random the random number generator to be used for selecting neighbors.
 */
public GraphFromQuery( final SimpleParser parser, final Object2ReferenceLinkedOpenHashMap<String,Index> indexMap, 
    final ImmutableGraph graph, final ImmutableGraph grapht, 
    final int maxIn, final int maxOut, final Random random ) {
  this.parser = parser;
  this.graph = graph;
  this.grapht = grapht;
  this.maxIn = maxIn;
  this.maxOut = maxOut;
  int n = graph.numNodes();
  
  if ( maxIn > 0 && maxIn < Integer.MAX_VALUE || maxOut > 0 && maxOut < Integer.MAX_VALUE ) {
    nodePermutation = Util.identity( n ); 
    IntArrays.shuffle( nodePermutation, random );
  } else nodePermutation = null;
  
  documentIteratorBuilderVisitor = new DocumentIteratorBuilderVisitor( indexMap, indexMap.get( parser.defaultIndex ), Integer.MAX_VALUE );
}

代码示例来源:origin: it.unimi.dsi/sux4j

if (! Modulo2System.lazyGaussianElimination(vertex2Edge, c, Util.identity(numVertices), solution)) {
  unsolvable++;
  if (LOGGER.isDebugEnabled()) LOGGER.debug("System is unsolvable");

代码示例来源:origin: it.unimi.dsi/sux4j

if (!Modulo2System.lazyGaussianElimination(vertex2Edge, c.clone(), Util.identity(maxNumVar), solution)) {
  unsolvable++;
  if (LOGGER.isDebugEnabled()) LOGGER.debug("System is unsolvable");

代码示例来源:origin: it.unimi.dsi/sux4j

if (! Modulo2System.lazyGaussianElimination(vertex2Edge, c, Util.identity(numVertices), solution)) {
  unsolvable++;
  if (LOGGER.isDebugEnabled()) LOGGER.debug("System is unsolvable");

代码示例来源:origin: it.unimi.dsi/sux4j

final int[] t = Util.identity(numVars);
final int[] u = new int[t.length];
final int[] count = new int[numEquations + 1]; // CountSort

代码示例来源:origin: it.unimi.dsi/sux4j

final int[] perm = Util.identity(bucket.length);
IntArrays.quickSort(perm, (a0, a1) -> Integer.compare(bucket[a1].size(), bucket[a0].size()));

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